Collections offer a tool to collect assets from different projects to an asset group, without uploading new assets or duplicate existing. You can add members to collection for collaboration or sharing, without them being members in the original project, and they won’t see to which project an asset belongs to.
Bear in mind, editing assets in a collection will affect the actual assets.
Collections are found in the sidebar and you can create a new collection at the bottom of the sidebar
Once the user has created a collection, assets can be added to collection either by clicking the collection icon next to favorites or with the bulk edit tool.